JP6004008B2 - Evaluation method and apparatus, processing method, and exposure system - Google Patents

Description

  The present invention relates to an evaluation technique for a substrate having a structure provided by processing under a plurality of processing conditions, a processing technique and an exposure technique using the evaluation technique, and a device manufacturing technique using the processing technique.

  In an exposure apparatus such as a scanning stepper or a stepper used in a lithography process for manufacturing a semiconductor device or the like, a dose amount (exposure amount), a focus position (a defocus amount of a substrate to be exposed with respect to an image plane of a projection optical system) ) And a plurality of exposure conditions such as the exposure wavelength must be managed with high accuracy. For this purpose, it is necessary to expose the substrate with an exposure apparatus and evaluate the actual exposure conditions of the exposure apparatus with high accuracy using a pattern or the like formed on the exposed substrate.

  For example, as a conventional method for evaluating the focus position of an exposure apparatus, a pattern for evaluation of a reticle is illuminated with illumination light whose chief ray is inclined, and an image of the pattern is displayed on a plurality of substrates while changing the height of the substrate on a stage. A method is known in which each shot is sequentially exposed, a lateral shift amount of a resist pattern obtained by development after exposure is measured, and a focus position at the time of exposure of each shot is evaluated from this measurement result (for example, Patent Documents) 1).

US Patent Application Publication No. 2002/0100012 US Patent Application Publication No. 2007/242247

In the conventional focus position evaluation method, there is a possibility that the measurement result also includes the influence of variation in the dose amount to some extent. In the future, in order to evaluate individual exposure conditions with higher accuracy, it is preferable to suppress the influence of other exposure conditions as much as possible.
Further, in the conventional method for evaluating the focus position, it is necessary to expose a dedicated evaluation pattern, and it is difficult to evaluate when exposing a pattern for an actual device.

  An aspect of the present invention has been made in view of such problems, and uses a substrate having a structure provided by processing under a plurality of processing conditions (for example, exposure conditions). The object is to evaluate one of the processing conditions with high accuracy.

According to the first aspect of the present invention, an illumination unit that illuminates a substrate having a structure provided by machining under a plurality of machining conditions including the first and second machining conditions with illumination light; and A detection unit for detecting light generated from the processing surface of the substrate by illumination light, and a detection result obtained by the detection unit under a plurality of diffraction conditions are calculated, and the first at the time of processing the substrate Under a plurality of evaluation conditions in which at least one of a calculation unit that outputs a calculation result for estimating a processing condition or the second processing condition and an illumination condition of the illumination unit and a detection condition of the detection unit are different based on the detection result obtained by the detection unit e Bei a first machining condition during processing of the substrate and the estimating unit that estimates at least one of its second working condition, wherein the detection unit, the Reflected or diffracted light from the work surface of the substrate Detecting the plurality of evaluation criteria, the diffraction conditions are different evaluation device is provided.

  Further, according to the second aspect, the exposure unit including the projection optical system that exposes the pattern on the surface of the substrate and the evaluation device of the first mode are estimated by the estimation unit of the evaluation device. An exposure system is provided that corrects a processing condition in the exposure unit in accordance with the first processing condition.

According to the third aspect, the substrate having the structure provided by processing under a plurality of processing conditions including the first and second processing conditions is illuminated with illumination light, and the illumination light emits the substrate The light generated from the processing surface of the substrate is detected, the detection result obtained by the detection unit is calculated under a plurality of diffraction conditions, and the first processing condition or the second processing condition when processing the substrate is calculated. The processing surface is calculated under a plurality of evaluation conditions in which at least one of the illumination condition of the illumination light and the detection condition of the light generated from the processing surface is different. And estimating at least one of the first processing condition and the second processing condition at the time of processing the substrate based on a detection result obtained by detecting light generated from the substrate, and a surface to be processed of the substrate When detecting light generated from Detecting reflected or diffracted light from the surface, the plurality of evaluation criteria, the diffraction conditions are different evaluation method is provided.

Further, according to the fourth aspect, a pattern is provided by processing on the surface of the substrate, the first processing condition of the substrate is estimated using the evaluation method of the third aspect, and is estimated by the evaluation method. A processing method is provided that corrects the processing conditions during exposure of the substrate in accordance with the first processing conditions.
Moreover, according to the 5th aspect, it is a device manufacturing method which has the processing process which provides a pattern on the surface of a board | substrate, Comprising: The device manufacturing method which uses the processing method of a 4th aspect at the processing process is provided.
Further, according to the sixth aspect, there is provided a device manufacturing method having a processing step of providing a pattern on the surface of the substrate, wherein the processing method according to the fourth aspect is used in the processing step according to the device to be manufactured. There is provided a device manufacturing method that stores an arithmetic expression to be applied to suppress a change amount with respect to a change in the second processing condition.

  According to the aspect of the present invention, using a substrate having a structure provided by processing under a plurality of processing conditions, one processing condition among the plurality of processing conditions can be evaluated with high accuracy.

(A) is a figure which shows the whole structure of the evaluation apparatus which concerns on embodiment, (b) is a block diagram which shows a device manufacturing system. (A) is a figure which shows the evaluation apparatus by which the polarizing filter was inserted on the optical path, (b) is a top view which shows an example of the pattern of the surface of a semiconductor wafer. (A) is an enlarged perspective view showing the concavo-convex structure of the repeating pattern, and (b) is a diagram showing the relationship between the incident surface of the linearly polarized light and the periodic direction (or repeating direction) of the repeating pattern. It is a flowchart which shows an example of the method (condition extraction) which calculates | requires evaluation conditions. It is a flowchart which shows the evaluation method of a dose amount. (A) is a plan view showing an example of the conditioned wafer 10, (b) is an enlarged view showing one shot, and (c) is an enlarged view showing an example of an arrangement of a plurality of setting areas in the shot. It is a figure which shows the image of the wafer imaged on the several diffraction conditions. (A) is a figure which shows several focus change curves, (b) is a figure which shows several dose change curves. (A) And (b) is a figure which shows the focus change curve and dose change curve which were measured on two diffraction conditions, respectively. (A) is a figure which shows the residual of a focus position, (b) is a figure which shows the difference of a dose amount. (A) is a figure which shows an example of distribution of the dose amount of a wafer surface, (b) is a figure which shows an example of distribution of the focus value of a wafer surface. (A) is a flowchart which shows the principal part of the other example of condition determination, (b) is a flowchart which shows the principal part of the evaluation method of a focus value. (A) And (b) is a figure which shows the dose change curve and focus change curve which were measured on two diffraction conditions, respectively. (A) is an enlarged cross-sectional view showing the main part of the wafer, (b) is an enlarged cross-sectional view showing the main part of another wafer, (c) is an enlarged cross-sectional view showing the wafer in the subsequent step of FIG. 14 (b), (D) is an enlarged sectional view showing a part of the pattern formed on the wafer, (e) is a diagram showing two spacer change curves and their residuals, and (f) is two etching change curves and their differences. FIG. (A) is a flowchart which shows an example of condition determination of 2nd Embodiment, (b) is a flowchart which shows the evaluation method of the etching of 2nd Embodiment. It is a flowchart which shows a semiconductor device manufacturing method.

[First Embodiment]
A preferred first embodiment of the present invention will be described below with reference to FIGS. FIG. 1A shows an evaluation apparatus 1 according to this embodiment, and FIG. 1B shows a device manufacturing system DMS according to this embodiment. In FIG. 1B, a device manufacturing system DMS includes a thin film forming apparatus (not shown) that forms a thin film on the surface (wafer surface) of a semiconductor wafer (hereinafter simply referred to as a wafer) that is a semiconductor substrate, and a resist for the wafer surface. A coater / developer 200 for applying and developing (photosensitive material), an exposure apparatus 100 for exposing a circuit pattern such as a semiconductor device on a wafer surface coated with a resist, and a structure formed on the wafer surface after exposure and development An evaluation apparatus 1 is provided that evaluates exposure conditions in the exposure apparatus 100 as processing conditions. As the exposure apparatus 100, for example, an immersion type scanning stepper (scanning projection exposure apparatus) disclosed in Patent Document 2 incorporated by reference is used. Further, the device manufacturing system DMS includes an etching apparatus that processes the developed wafer, a transfer system 500 that transfers the wafer between these apparatuses, and a host computer 600 that mediates control information between these apparatuses. I have.

  1A, the evaluation apparatus 1 includes a stage 5 that supports a substantially disk-shaped wafer 10, and the wafer 10 transferred by the transfer system 500 in FIG. Is mounted and fixed and held, for example, by vacuum suction. The stage 5 rotates through a first drive unit (not shown) that controls an angle φ1 with the central axis of the stage 5 as a rotation axis, and an axis that passes through the top surface of the stage 5 and is perpendicular to the paper surface of FIG. It is supported by a base member (not shown) via a second drive unit (not shown) that controls a tilt angle φ2 (tilt angle of the surface of the wafer 10) that is an inclination angle as an axis.

  The evaluation apparatus 1 further includes an illumination system 20 that irradiates illumination light ILI as parallel light onto the surface (wafer surface) of the wafer 10 supported by the stage 5, and light emitted from the wafer surface that has been irradiated with the illumination light ILI ( A light receiving system 30 that collects reflected light or diffracted light), an imaging device 35 that receives the light collected by the light receiving system 30 and detects an image on the wafer surface, and an image signal output from the imaging device 35 And an arithmetic unit 50 that performs processing and the like. The imaging device 35 includes an imaging lens 35a that forms an image on the wafer surface and a CCD or CMOS type two-dimensional imaging device 35b. The imaging device 35b collectively captures an image of the entire surface of the wafer 10. Output an image signal. Based on the image signal of the wafer 10 input from the imaging device 35, the calculation unit 50 averages the digital image of the wafer 10 (the luminance for each pixel, the luminance averaged for each shot, or for each region smaller than the shot. Image processing unit 40 that generates information on brightness, etc., an inspection unit 60 that includes arithmetic units 60a, 60b, and 60c that process image information output from the image processing unit 40, and an image processing unit 40 and an inspection unit 60. A control unit 80 for controlling the operation of the image, a storage unit 85 for storing information about the image, and the evaluation result of the obtained exposure conditions to a control unit (not shown) in the exposure apparatus 100 via the host computer 600. And a signal output unit 90 for outputting. The calculation unit 50 may be configured as a computer as a whole, and the inspection unit 60, the control unit 80, and the like may be functions on the software of the computer.

  The illumination system 20 includes an illumination unit 21 that emits illumination light, and an illumination-side concave mirror 25 that reflects the illumination light emitted from the illumination unit 21 toward the wafer surface as parallel light. The illumination unit 21 selects light of a predetermined wavelength (for example, wavelengths λ1, λ2, λ3, etc.) from light from the light source unit 22 such as a metal halide lamp or a mercury lamp and the light from the light source unit 22 according to a command from the control unit 80. The light control unit 23 that adjusts the intensity, and the light guide fiber 24 that emits light selected by the light control unit 23 and adjusted in intensity from a predetermined emission point to the illumination-side concave mirror 25. As an example, the wavelength λ1 is 248 nm, λ2 is 265 nm, and λ3 is 313 nm. In this case, since the exit portion of the light guide fiber 24 is disposed on the focal plane of the illumination-side concave mirror 25, the illumination light ILI reflected by the illumination-side concave mirror 25 is irradiated as a parallel light beam onto the wafer surface. The incident angle θ1 of the illumination light with respect to the wafer 10 can be adjusted by controlling the tilt angle φ2 of the stage 5 according to a command from the control unit 80.

  Further, between the light guide fiber 24 and the illumination-side concave mirror 25, an illumination-side polarizing filter 26 is provided on the optical path so that it can be inserted into and removed from the optical path by a drive unit (not shown) based on a command from the control unit 80. As shown in FIG. 1A, in a state where the illumination side polarizing filter 26 is removed from the optical path, an inspection using the diffracted light ILD from the wafer 10 (hereinafter referred to as a diffraction inspection for convenience) is performed. On the other hand, as shown in FIG. 2A, in the state where the illumination-side polarizing filter 26 is inserted in the optical path, an inspection using polarized light (change in polarization state due to structural birefringence) (hereinafter, PER inspection for convenience). Is performed). The illumination side polarizing filter 26 is, for example, a linear polarizing plate whose rotation angle can be controlled. Even at the time of diffraction inspection, the illumination side polarization filter 26 is arranged on the optical path so that the illumination light ILI becomes S-polarized light (linearly polarized light in a direction perpendicular to the incident surface) with respect to the surface of the wafer 10. Is also possible. In the diffraction inspection using S-polarized light, it is difficult to be influenced by the underlayer of the wafer 10, and the state of the uppermost layer can be detected.

The light receiving system 30 includes a light receiving side concave mirror 31 disposed to face the stage 5 (wafer 10), and an incident portion of the imaging device 35 is disposed on the focal plane of the light receiving side concave mirror 31. For this reason, the parallel light emitted from the wafer surface is collected by the light receiving side concave mirror 31 onto the image pickup device 35, and an image of the wafer 10 is formed on the image pickup surface of the image pickup device 35 b of the image pickup device 35.
In addition, a light receiving side polarizing filter 32 is provided between the light receiving side concave mirror 31 and the imaging device 35 so that the light receiving side polarizing filter 32 can be inserted into and removed from the optical path by a drive unit (not shown) based on a command from the control unit 80. As shown in FIG. 1A, the diffraction inspection is performed with the light-receiving side polarizing filter 32 taken out from the optical path. On the other hand, as shown in FIG. 2A, the PER inspection is performed with the light receiving side polarizing filter 32 inserted in the optical path. Similarly to the illumination-side polarizing filter 26, the light-receiving-side polarizing filter 32 is a linear polarizing plate whose rotation angle can be controlled, for example. In the PER inspection, the polarization direction of the light-receiving side polarizing filter 32 is normally set in a crossed Nicols state orthogonal to the polarization direction of the illumination-side polarizing filter 26.

  The inspection unit 60 compares the digital image of the wafer 10 supplied from the image processing unit 40 with the image data of the non-defective wafer stored in the storage unit 85 as the most basic operation in response to a command from the control unit 80. The wafer surface is inspected for defects (abnormalities). Then, the inspection result by the inspection unit 60 and the image of the wafer surface at that time are output and displayed by an image display device (not shown). In the present embodiment, the inspection unit 60 processes the image of the wafer surface as will be described later, the dose amount (exposure amount or exposure energy) of the exposure apparatus 100 that has exposed the wafer 10, and the focus position (projection optics of the exposure surface). Among a plurality of exposure conditions such as the position of the system in the optical axis direction), the exposure wavelength (center wavelength and / or half-value width), and the temperature of the liquid between the projection optical system and the wafer in the case of exposure by the immersion method The predetermined exposure conditions are evaluated. The evaluation result of the exposure condition is supplied to a control unit (not shown) in the exposure apparatus 100, and the exposure apparatus 100 may correct the exposure condition (for example, correction of offset or variation) according to the evaluation result. it can.

  A predetermined pattern is projected and exposed on the uppermost resist by the exposure apparatus 100, and the wafer 10 is transported onto the stage 5 of the evaluation apparatus 1 by the transport system 500 after development by the coater / developer 200. At this time, the wafer 10 is aligned on the basis of a pattern in the shot of the wafer 10, a mark on the wafer surface (for example, a search alignment mark), or an outer edge (notch, orientation flat, etc.) by an alignment mechanism (not shown) in the middle of conveyance. In the performed state, it is conveyed onto the stage 5. On the wafer surface, as shown in FIG. 2B, a plurality of shots (shot regions) 11 are arranged at predetermined intervals in two directions (X direction and Y direction) orthogonal to each other. Inside, a repetitive pattern 12 of irregularities such as a line pattern or a hole pattern is formed as a circuit pattern of a semiconductor device. Note that an axis perpendicular to the XY plane is taken as a Z axis. The repeating pattern 12 may be a resist pattern, for example. Although one shot 11 often includes a plurality of chip areas, FIG. 2B shows that one chip area is included in one shot for easy understanding.

  In order to perform diffraction inspection of the wafer surface (inspection performed by detecting the diffracted light ILD from the wafer 10) using the evaluation apparatus 1 configured as described above, the control unit 80 is stored in the storage unit 85. Recipe information (inspection conditions, procedures, etc.) is read and the following processing is performed. First, as shown in FIG. 1A, the illumination side polarizing filter 26 and the light receiving side polarizing filter 32 are taken out from the optical path, and the wafer 10 is transferred onto the stage 5 by the transfer system 500. Note that the wafer 10 is placed at a predetermined position on the stage 5 in a predetermined direction based on position information of the wafer 10 obtained by an alignment mechanism (not shown) during the conveyance.

  Next, the direction of the incident surface of the illumination light ILI on the wafer surface (illumination direction) and the periodic direction (or repeat direction) of the repetitive pattern 12 in each shot 11 coincide (in the case of a line pattern, the line The angle φ1 of the stage 5 is adjusted so as to be orthogonal to each other. Further, the pitch of the repetitive pattern 12 is P, the wavelength of the illumination light ILI incident on the wafer 10 is λ, the incident angle of the illumination light ILI is θ1, and the nth order of the detection target emitted from the wafer surface (n is an integer other than 0) When the diffraction angle of the diffracted light ILD is θ2, the tilt angle φ2 of the stage 5 is adjusted so as to satisfy the following equation (Equation 1).

  Next, emission of illumination light ILI having a predetermined selected wavelength from the illumination unit 21 is started. As a result, the illumination light ILI emitted from the light guide fiber 24 is reflected by the illumination-side concave mirror 25 and is irradiated onto the wafer surface as parallel light. The diffracted light ILD diffracted on the wafer surface is condensed on the image pickup device 35 by the light receiving side concave mirror 31, and an image (diffraction image) of the entire surface of the wafer 10 is formed on the image pickup surface of the image pickup device 35. The imaging device 35 outputs an image signal of the image to the image processing unit 40, and the image processing unit 40 generates a digital image of the wafer surface and outputs information on the image to the inspection unit 60. In this case, by satisfying the condition of the above mathematical formula (Equation 1), an image of the wafer surface by the diffracted light ILD is formed on the imaging surface.

  Then, the wavelength λ of the illumination light ILI when the level of each image signal of the digital image obtained from the image on the wafer surface (the luminance of the image of the corresponding portion) is equal to or greater than an intensity (luminance) on average. A combination of the tilt angle φ2 (incident angle θ1 or diffraction angle θ2) of the stage 5 is called one diffraction condition. A plurality of diffraction conditions are included in the recipe information. In practice, the tilt angle φ2 of the stage 5 may be adjusted so that the brightness of the image of the corresponding part of the obtained digital image is equal to or higher than a certain brightness on average. Such a method of adjusting the tilt angle φ2 can also be called a diffraction condition search.

  Next, a PER inspection (inspection based on a change in the polarization state of reflected light) of the wafer surface by the evaluation apparatus 1 will be described. In this case, the repetitive pattern 12 on the wafer surface of FIG. 2B is along the arrangement direction (here, the X direction) in which the plurality of line portions 2A are short directions, as shown in FIG. It is assumed that the resist patterns (line patterns) are arranged at a constant pitch (period) P with the space portion 2B interposed therebetween. The arrangement direction (X direction) of the line portions 2A is also referred to as a periodic direction (or a repeating direction) of the repeating pattern 12.

Here, the design value of the line width D _A of the line portion 2A in the repetitive pattern 12 is set to ½ of the pitch P. If repeated pattern 12 is formed as designed, the line width D _B of the line width D _A and the space portion 2B of the line portion 2A are equal, the volume ratio of the line portion 2A and the space portion 2B is substantially 1: 1 become. On the other hand, when the focus position in the exposure apparatus 100 when forming the repeated pattern 12 deviates from the best focus position (appropriate value), the pitch P does not change, but the line width D _{A of the} line portion 2A and the space portion 2B. , D _B is becomes different from a design value, the volume ratio of the line portion 2A and the space portion 2B is substantially 1: deviates from 1.

  The PER inspection uses the change in the polarization state of the reflected light accompanying the change in the volume ratio between the line portion 2A and the space portion 2B in the repetitive pattern 12 as described above to inspect the state (good or bad) of the repetitive pattern 12. Is to do. In order to simplify the description, the ideal volume ratio (design value) is 1: 1. The change in the volume ratio is caused by a shift of the focus position from the appropriate value, and appears for each shot 11 of the wafer 10 and for each of a plurality of regions in the shot 11. The volume ratio can also be referred to as the area ratio of the cross-sectional shape.

  In order to perform the PER inspection of the wafer surface using the evaluation apparatus 1 of the present embodiment, the control unit 80 reads recipe information (inspection conditions, procedures, etc.) stored in the storage unit 85 and performs the following processing. First, as shown in FIG. 2A, the illumination side polarizing filter 26 and the light receiving side polarizing filter 32 are inserted on the optical path. Then, the wafer 10 is transferred onto the stage 5 by the transfer system 500 of FIG. Note that the wafer 10 is placed at a predetermined position on the stage 5 in a predetermined direction based on position information of the wafer 10 obtained by an alignment mechanism (not shown) during the conveyance. Further, when performing the PER inspection, the tilt angle of the stage 5 is set so that the regular reflection light ILR from the wafer 10 can be received by the light receiving system 30, that is, the incident angle of the incident illumination light ILI (the angle in FIG. 2A). The angle of reflection of the light received by the light receiving system 30 with respect to the wafer surface is set to be equal to θ3). Furthermore, the rotation angle of the stage 5 is such that the periodic direction of the repetitive pattern 12 on the wafer surface is such that the illumination light on the wafer surface (in FIG. 3B, P-polarized linearly polarized light L as shown in FIG. 3B). It is set to incline at 45 degrees with respect to the vibration direction. This is because the signal intensity of the reflected light from the repeated pattern 12 is maximized. If the detection sensitivity (the ratio of the change in the detection signal to the change in the exposure condition) is increased by setting the angle between the periodic direction and the vibration direction to 22.5 degrees or 67.5 degrees, the angle is set to It may be changed. The angle is not limited to these and can be set to an arbitrary angle.

  The illumination side polarizing filter 26 is disposed between the light guide fiber 24 and the illumination side concave mirror 25, and its transmission axis is set in a predetermined direction (direction). A polarized component (linearly polarized light) is extracted (transmitted) from the light. In the present embodiment, as an example, light emitted from the light guide fiber 24 becomes P-polarized linearly polarized light L (see FIG. 3B) via the illumination-side polarizing filter 26 and the illumination-side concave mirror 25, and the wafer surface. Is irradiated.

  At this time, since the illumination light ILI incident on the wafer surface (here, linearly polarized light L) is P-polarized light, as shown in FIG. When the angle is set to 45 degrees with respect to the traveling direction of the light L on the wafer surface, the angle formed by the vibration direction of the light L on the wafer surface and the periodic direction of the repeated pattern 12 is also set to 45 degrees. In other words, the linearly polarized light L is incident so as to obliquely cross the repetitive pattern 12 in a state where the vibration direction of the light L on the wafer surface is inclined 45 degrees with respect to the periodic direction of the repetitive pattern 12.

  The parallel specular light ILR reflected by the wafer surface is collected by the light receiving concave mirror 31 of the light receiving system 30 and reaches the image pickup surface of the image pickup device 35 via the light receiving side polarizing filter 32. At this time, the polarization state of the specularly reflected light ILR (here, linearly polarized light L) is changed to, for example, elliptically polarized light due to structural birefringence in the repeated pattern 12. The direction of the transmission axis of the light receiving side polarizing filter 32 is set so as to be orthogonal to the transmission axis of the illumination side polarizing filter 26 described above (in a crossed Nicols state). Therefore, the light receiving side polarization filter 32 extracts a polarized component having a vibration direction substantially perpendicular to the light L from the regular reflected light from the wafer 10 (repeated pattern 12) and guides it to the imaging device 35. As a result, on the image pickup surface of the image pickup device 35, the wafer surface is formed of a polarization component (the S polarization component if the light L is P-polarized light) whose oscillation direction is substantially perpendicular to the light L in the regular reflection light from the wafer 10. Is formed. When the minor axis direction of the elliptically polarized light is not orthogonal to the polarization direction of the light L, the transmission axis of the light receiving side polarizing filter 32 may be aligned with the minor axis direction of the elliptically polarized light. This may improve the detection sensitivity (the ratio of the change in the detection signal to the change in the exposure condition).

  Then, the imaging device 35 outputs an image signal of the image on the wafer surface to the image processing unit 40, and the image processing unit 40 generates a digital image of the wafer surface and outputs information on the image to the inspection unit 60. The inspection unit 60 evaluates the exposure conditions and the like in the exposure apparatus used when forming the repetitive pattern 12 of the wafer 10 using the image information. It is also possible to shift the polarization direction of the illumination light ILI incident on the wafer surface by rotating the illumination-side polarization filter 26 from the P-polarized light. However, even in this case, the polarization direction of the light receiving side polarizing filter 32 is set in a crossed Nicols state with respect to the illumination side polarizing filter 26. When such a digital image is generated, a combination of the wavelength λ of the illumination light ILI and the angle of the illumination side polarization filter 26 is referred to as one polarization condition. For example, it is possible to provide a mechanism for changing the incident angle θ3 (that is, the reflection angle θ3) of the illumination light ILI. When the incident angle is changed in this way, the incident angle is also included in one polarization condition. . A plurality of polarization conditions are included in the recipe information.

  Next, in the present embodiment, an example of a method for detecting light from a pattern on a wafer surface using the evaluation apparatus 1 and evaluating the exposure conditions of the exposure apparatus 100 used when forming the pattern is shown in FIG. This will be described with reference to the flowchart of FIG. Further, since it is necessary to obtain an evaluation condition in advance for the evaluation, an example of a method for obtaining the evaluation condition (hereinafter also referred to as “conditioning”) will be described with reference to the flowchart of FIG. Here, as an example, the wafer surface diffraction inspection (inspection performed by detecting the diffracted light ILD from the wafer 10) is performed using the evaluation apparatus 1. For this reason, as shown in FIG. 1A, the illumination side polarizing filter 26 and the light receiving side polarizing filter 32 are taken out from the optical path of the evaluation device 1. Furthermore, the dose amount is evaluated among a plurality of exposure conditions including the dose amount and the focus position of the exposure apparatus 100.

  First, in order to set conditions, in step 102 (preparation of conditionally adjusted wafer) in FIG. 4, as shown in FIG. 6A, as an example, N pieces (N is, for example, several 10 to 10) with the scribe line region SL interposed therebetween. A wafer 10a on which shots SAn (n = 1 to N) of about 100 integers are arranged is prepared. Then, the resist-coated wafer 10a is transported to the exposure apparatus 100 of FIG. 1B, and the exposure apparatus 100 performs, for example, between shots arranged in the scanning direction (longitudinal direction of the shot) of the wafer 10a during scanning exposure. The same actual value is applied to each shot SAn while changing the exposure condition so that the focus position changes gradually and the dose amount gradually changes between shots arranged in the non-scanning direction (short shot side direction) orthogonal to the scanning direction. A pattern of a reticle (not shown) for the device is exposed. At this time, in order to improve the control accuracy of the focus position and the dose amount, for example, the scanning speed at the time of scanning exposure may be decreased. Thereafter, by developing the exposed wafer 10a, a wafer 10a (hereinafter referred to as a “conditional wafer”) in which the pattern 12 is repeatedly formed on each shot SAn under different exposure conditions is created.

  Normally, a reticle for an actual device is formed with a plurality of patterns having the same or orthogonal periodic directions at a plurality of pitches, and each shot SAn has a pattern with a different pitch in addition to the repeating pattern 12 of the pitch P. It is formed. Furthermore, for example, when there is a pattern block in which a repetitive pattern of pitch P is arranged at a larger pitch P1 (> P), the same diffracted light as that generated from the pattern of pitch P1 is generated from this pattern block. It is also possible to perform a diffraction inspection on the assumption that there is a pattern with a pitch P1 substantially.

  Hereinafter, as the focus position, the best focus position (the best focus position is a position where the fluctuation of the line width becomes the smallest when the focus is moved to ±. However, in this specification, it is set to the exposure apparatus 100. It is assumed that a defocus amount (referred to herein as a focus value) is used. With respect to the focus position, for example, the focus value is set in five steps of −60 nm, −30 nm, 0 nm, +30 nm, and +60 nm in increments of 30 nm. The horizontal focus value numbers 1 to 5 in FIG. 8A described later correspond to the five focus values (−60 to +60 nm). Note that the focus value can be set in a plurality of stages in increments of 50 nm, for example, and the focus value can be set in 17 stages of −200 nm to +200 nm in increments of 25 nm, for example.

  For example, the dose amount is 9 steps in increments of 1.5 mJ (10.0 mJ, 11.5 mJ, 13.0 mJ, 14.5 mJ, 16.0 mJ, 17.5 mJ, 19.0 mJ, 20.5 mJ, 22 .0mJ). Numbers 1 to 9 on the horizontal axis in FIG. 8B described later correspond to the nine levels of dose (10.0 to 22.0 mJ). The optimum exposure amount (best dose) required for the exposure of the pattern for an actual semiconductor device is about 5 mJ to 40 mJ depending on the pattern, and the dose amount is 0.5 mJ to 2.0 mJ centering on the best dose of the pattern. It is desirable to change at a certain interval.

  The conditionally adjusted wafer 10a of the present embodiment is a so-called FEM wafer (Focus Exposure Matrix wafer) that is exposed and developed with a dose amount (exposure amount or exposure energy) and a focus position being shaken in a matrix. If the number of shots with different combinations of exposure conditions obtained by multiplying the number of focus value stages by the number of dose stages is greater than the number of shots on the entire surface of the conditionally adjusted wafer 10a, the conditionally adjusted wafer 10a is Multiple sheets may be created.

  Conversely, for example, when the number of shots SAn in the scanning direction is larger than the number of stages of change in the focus value, and / or when the number of arrangements in the non-scanning direction is larger than the number of stages of change in the dose amount, scanning is performed. Only a part of the shots arranged in the direction and / or the non-scanning direction may be exposed. However, in this case, even if a plurality of shots exposed by changing the focus value and the dose amount are provided in the scanning direction or the non-scanning direction, the measurement values obtained for the shots having the same focus value and the dose amount may be averaged. Good. Further, for example, the influence of unevenness in resist coating between the central portion and the peripheral portion of the wafer and the influence of the difference in the scanning direction of the wafer during scanning exposure (the + Y direction or the −Y direction in FIG. 2B) are reduced. Therefore, a plurality of shots having different focus values and dose amounts may be arranged at random.

  When the conditioned wafer 10a is created, the conditioned wafer 10a is transferred onto the stage 5 of the evaluation apparatus 1 in FIG. Then, the control unit 80 reads out a plurality of diffraction conditions from the recipe information in the storage unit 85. As a plurality of diffraction conditions, for example, the wavelength λ of the illumination light ILI is any one of the above λ1, λ2, and λ3, and the tilt angle φ2 of the stage 5 has five angles D1 to D5 that satisfy the above formula (Equation 1). Assume 15 (= 3 × 5) conditions to be either. Here, a diffraction condition in which the wavelength λ is λn (n = 1 to 3) and the tilt angle φ2 is Dm (m = 1 to 5) is represented by (n−Dm) in FIGS. 8A and 8B. .

  The diffraction conditions are sequentially set to the conditions of n = 1 of the 15 conditions, m = 1 to 5, n = 2, m = 1 to 5, n = 3, and m = 1 to 5. Under the diffraction conditions, the illumination light ILI is irradiated onto the surface of the conditionally adjusted wafer 10a, and the imaging device 35 picks up an image of the diffracted light of the conditionally adjusted wafer 10a and outputs an image signal to the image processing unit 40 (step). 104). At this time, the diffraction condition may be obtained using a diffraction condition search. FIG. 7 shows an example of the luminance distribution of the images A1 to A15 of the conditioned wafer 10a imaged under the 15 diffraction conditions (n-Dm).

  Next, based on the image signal of the conditioned wafer 10a input from the imaging device 35, the image processing unit 40 outputs a digital image of the entire surface of the conditioned wafer 10a with respect to each of a plurality of (here, 15) diffraction conditions. Generate. Then, with respect to the plurality of diffraction conditions, using the corresponding digital images, the signal intensities of all the pixels in all the shots SAn (see FIG. 6B) excluding the scribe line region SL of the conditionally adjusted wafer 10a. The average signal intensity obtained by averaging is calculated, and the calculation result is output to the inspection unit 60 (step 106). The average signal intensity is also referred to as shot average luminance (or in-shot average luminance). The reason why the shot average luminance is calculated in this way is to suppress the influence of the aberration of the projection optical system of the exposure apparatus 100 and the like. In order to further suppress the influence of the aberration and the like, for example, an average signal intensity (average luminance) obtained by averaging the signal intensities of all the pixels in the partial area CAn in the central portion of the shot SAn in FIG. It may be calculated.

  However, the influence of the aberration of the projection optical system (error distribution given to the digital image) can be obtained in advance, and the influence of the aberration can be corrected at the stage of the digital image. In this case, instead of the shot average luminance, the average signal intensity (average luminance) is set for each of the setting areas 16 (see FIG. 6C) such as a rectangle (I is an integer of several tens) in the shot SAn. ), And the subsequent processing may be performed using, for example, the average luminance of the setting area 16 at the same position in the shot SAn. The arrangement of the setting areas 16 is, for example, 6 rows in the scanning direction and 5 columns in the non-scanning direction, but the size and arrangement are arbitrary.

  And the 1st calculating part 60a in the test | inspection part 60 has the same dose amount in exposure conditions from all the shot average brightness | luminances of the condition adjustment wafer 10a obtained regarding each of the several diffraction conditions (n-Dm). The change characteristic of the average luminance when the focus value changes in five steps is extracted as a focus change curve and stored in the storage unit 85 (step 108). FIG. 8A shows a plurality (15 in this case) of focus change curves obtained under the diffraction condition (n-Dm) when the dose is the best dose. 8A and 8B, the vertical axis represents the relative value of the shot average luminance, and the horizontal axis of FIG. 8A represents the first to fifth focus values (-100 to +100 nm).

  Further, the first calculation unit 60a determines that the focus value in the exposure condition is the same and the dose amount is changed in nine steps from all shot average luminances obtained for each of the plurality of diffraction conditions (n-Dm). Is extracted as a dose change curve and stored in the storage unit 85 (step 110). FIG. 8B shows a plurality of dose change curves obtained under the diffraction condition (n−Dm) when the focus value is 0 (best focus position). The horizontal axis of FIG.8 (b) is the dose amount (10.0-22.0mJ) of a 1st step-a 9th step.

  Thereafter, the first calculation unit 60a has the same tendency (for example, the characteristic that both shot average luminances increase and decrease in substantially the same manner when the focus value increases) from the plurality of diffraction conditions described above, The first and second diffraction conditions are selected such that the dose change curve has a reverse tendency (for example, the characteristic that one shot average luminance increases substantially and the other shot average luminance decreases approximately when the dose increases). The two selected diffraction conditions are stored in the storage unit 85 (step 112). In the present embodiment, (1-D2) of (n = 1, m = 2) and (3-D3) of (n = 3, m = 3) are selected as such first and second diffraction conditions. To do. FIG. 9A shows two focus change curves B2 and B13 obtained under the diffraction conditions (1-D2) and (3-D3) among the 15 focus change curves in FIG. 8A. FIG. 9B shows two dose change curves C2 obtained under the diffraction conditions (1-D2) and (3-D3) among the 15 change curves in FIG. 8B. And C13. It can be seen that the focus change curves B2 and B13 change with the same tendency, and the dose change curves C2 and C13 change with the opposite tendency.

  The first computing unit 60a then corrects the focus change curve B2 obtained under the first diffraction condition (1-D2) with the gain a (arbitrary magnification or proportional coefficient) and the offset b (see FIG. a) and the focus change curve B13 obtained under the second diffraction condition (3-D3), that is, the difference between the corrected curve B2A and the focus change curve B13 (hereinafter referred to as the focus remaining curve). The gain a and the offset b are determined so that ΔB is minimized, and the gain a and the offset b are stored in the storage unit 85 (step 114). The vertical axis on the right side of FIG. 10A is the value of the focus residual ΔB. In this case, as an example, the values when the focus values of the focus change curves B2 and B13 are Fi (i = 1 to 5) are LB2 (Fi) and LB13 (Fi), and an error that is the square sum of the following differences is obtained. The gain a and the offset b may be determined so as to be minimized. In the case of FIG. 9A, the value of the curve B2 is larger than that of the curve B13, and thus the gain a is smaller than 1. Integration in the following mathematical formula (Equation 2) is executed with respect to the focus value Fi (i = 1 to 5).

The gain a and the offset b may be determined and stored for each reticle pattern to be exposed.
Further, a curve obtained by correcting the focus change curve B12 obtained under the second diffraction condition (3-D3) with the gain a ′ (proportional coefficient or magnification) and the offset b ′, and the first diffraction condition (1-D2). The gain a ′ and the offset b ′ may be determined so that the focus change curve B2 obtained in step 1 matches. Further, even if the curve B2A and the focus change curve B13 are approximated by a high-order polynomial (for example, a fourth-order polynomial) regarding the focus value Fi, the values of a and b are determined so that the square sum of these differences is minimized. Good. Alternatively, only the gain a or the offset b may be used to correct one focus change curve, and the value of a or b may be determined so that the corrected curve matches the other focus change curve as much as possible. . Further, for example, for each focus value Fi, the coefficient cfi to be multiplied by one focus change curve may be determined independently so that the corrected difference becomes zero.
Note that there is a tendency that the characteristics of the two focus change curves are contradictory (for example, one curve FA1 changes to a convex shape and the other curve FB1 changes to a concave shape with respect to a change in the focus value Fx), and a dose. It is also possible to use two diffraction conditions in which the characteristics of the change curve have the same tendency (for example, the two curves DA1 and DA2 increase or decrease almost monotonously with respect to the change in dose). In this case, if one curve FA1 is a function (fa (Fx) + fb1) (fb is a constant), the other curve FB1 is almost a function (−fb1 · fa (Fx) + fb2) (fb1, fb2 are constants, fb1 Is positive), and the gain a1 for adjusting the curve FB1 to the curve FA1 has a negative value of -1 / fb1. For this reason, the calculation in the parenthesis on the right side of the equation (Equation 2) is the sum of the curve FA1 and the value obtained by multiplying the curve FB1 by a constant (1 / fb1) with respect to the gain a1.

  Next, the first calculation unit 60a corrects the dose change curve C2 obtained under the first diffraction condition (1-D2) in FIG. 9B with the gain a and the offset b calculated in step 114. A curve representing the difference (dose difference) between C2A (see FIG. 10B) and the dose change curve C13 obtained under the second diffraction condition (3-D3) (hereinafter referred to as a reference dose). SD1 is calculated, and the calculated reference dose curve SD1 of FIG. 10B is stored in the storage unit 85 (step 116). In addition, the vertical axis | shaft of the right side of FIG.10 (b) is a value of a dose difference. Further, the reference dose curve SD1 may be approximated by a linear expression or a high-order polynomial regarding the dose amount. With the above operation, the condition determination for obtaining the first and second diffraction conditions, which are the evaluation conditions used when evaluating the exposure conditions of the exposure apparatus 100, is completed.

  Next, two diffraction conditions (1-D2) and (3-) obtained by the evaluation apparatus 1 under the above-described conditions for a wafer on which a pattern is formed by exposure by the exposure apparatus 100 in an actual device manufacturing process. By performing the diffraction inspection using D3), the dose amount in the exposure condition of the exposure apparatus 100 is evaluated as follows. This evaluation operation can also be called a dose monitor. First, in step 120 of FIG. 5, the wafer 10 for actual exposure having the same shot arrangement as that of FIG. 6A and coated with a resist is transferred to the exposure apparatus 100 of FIG. A pattern of a reticle (not shown) for an actual device is exposed to each shot SAn (n = 1 to N) of the wafer 10, and the exposed wafer 10 is developed. The exposure conditions at this time are the best dose determined in accordance with the reticle with respect to the dose amount in all shots, and the best focus position with respect to the focus position.

  However, in actuality, due to the influence of, for example, slight illuminance unevenness in the slit-like illumination area during scanning exposure in the exposure apparatus 100, for example, a plurality of shots SAn of the wafer 10 and a plurality of shots SAn. Since there is a possibility that the dose amount varies for each setting region 16, the dose amount is evaluated. Further, due to the influence of vibration or the like in the exposure apparatus 100, the focus position may vary for each shot SAn and for each of the plurality of setting areas 16 in each shot SAn. In this case, if the diffraction inspection is simply performed, the inspection result includes a portion due to the focus position in addition to the dose amount, so the influence of the focus position is eliminated as follows.

The wafer 10 after exposure and development is loaded onto the stage 5 of the evaluation apparatus 1 in FIG. 1A through an alignment mechanism (not shown) (step 122). And the control part 80 reads the 1st and 2nd diffraction conditions (1-D2) and (3-D3) determined by said condition determination from the recipe information of the memory | storage part 85. FIG. Then, the diffraction conditions are sequentially set to the first and second diffraction conditions, and the illumination light ILI is irradiated on the surface of the wafer 10 under each diffraction condition. An image is captured and an image signal is output to the image processing unit 40 (step 124).
It should be noted that, in step 104 in the condition setting step of FIG. 4 described above, the first diffraction condition (1) among the conditioned wafer images A1 to A13 shown in FIG. 7 obtained under a plurality of diffraction conditions. The image obtained under -D2) is image A2, and the image obtained under the second diffraction condition (3-D3) is image A13. For this reason, the brightness of the image of each part of the wafer 10 imaged under the first and second diffraction conditions is the dose amount and the focus value of the part of the wafer 10 in the images A2 and A13, respectively. It becomes almost the same as the brightness of the image of the part which becomes almost the same in the conditionally adjusted wafer.

  Next, the image processing unit 40 generates a digital image of the entire surface of the wafer 10 with respect to each of the first and second diffraction conditions based on the image signal of the wafer 10 input from the imaging device 35. Then, with respect to the first and second diffraction conditions, the average signal intensity for each of the I setting regions 16 (see FIG. 6C) in all shots SAn of the wafer 10 using the corresponding digital images. (Average luminance) is calculated, and the calculation result is output to the inspection unit 60 (step 126). Instead of the setting area 16, an area corresponding to each pixel of the image sensor of the imaging device 35 may be used. Here, the average luminances obtained in the i-th setting region 16 in the n-th shot under the first and second diffraction conditions are L1ni and L2ni, respectively (n = 1 to N, i = 1 to 1). I). Each of these average luminances includes two values, a focus change curve and a dose change curve.

  Then, the third calculation unit 60c in the inspection unit 60 calculates the average luminance L1ni obtained in the first diffraction condition (1-D2) in the above step 114 for every setting region 16 of the wafer 10. The average luminance difference Δni obtained by subtracting the average luminance L2ni obtained under the second diffraction condition (3-D3) from the luminance L1ni ′ corrected with the gain a and the offset b is calculated, and the calculation result is stored in the storage unit 85. (Step 128). From this difference Δni, components corresponding to the corrected focus change curves B2A and B13 in FIG. 10A are almost removed, and the difference between the corrected dose change curves C2A and C13 in FIG. Only the corresponding component is almost left.

  Therefore, the third calculation unit 60c applies the difference Δni in the average luminance to the reference dose curve SD1 in FIG. 10B stored in the above step 116 for every setting region 16 of the wafer 10 and corresponds. The dose amount Dni is calculated or estimated, and the calculation result or the estimation result is stored in the storage unit 85 (step 130). The component resulting from the focus position is removed from the dose amount Dni calculated or estimated in this way. Thereafter, the control unit 80 converts the dose amount Dni into, for example, brightness (or the color may be changed), and obtains a dose distribution on the entire surface of the wafer 10 (for example, a distribution represented by the image in FIG. 11A). The information is displayed on a display device (not shown) (step 132). Further, under the control of the control unit 80, information on the dose distribution of the entire surface of the wafer 10 is provided from the signal output unit 90 to the exposure apparatus 100 via the host computer 600 (step 134). In response to this, a control unit (not shown) of the exposure apparatus 100 obtains, for example, a difference distribution between the dose distribution and the best dose, and when the difference distribution exceeds a predetermined allowable range, for example, scanning exposure is performed. Correction of the distribution of the width in the scanning direction of the illumination area at the time is performed. This reduces errors in dose distribution during subsequent exposure.

According to this embodiment, the wafer 10 on which the pattern for the actual device is formed is subjected to diffraction inspection under two diffraction conditions, whereby the exposure condition of the exposure apparatus 100 used at the time of forming the pattern. The dose amount in the medium can be estimated or evaluated with high accuracy by removing the influence of the focus position.
As described above, the evaluation apparatus 1 of the present embodiment has the concave and convex repeated pattern 12 (by the exposure under a plurality of exposure conditions including the dose amount and the focus position (first and second exposure conditions) ( An illumination system 20 that illuminates the wafer 10 having a structure with illumination light, a light receiving system 30 that detects light generated from the surface (exposure surface) of the wafer 10 by the illumination light, and an imaging unit 35 (detection unit); First and second diffraction conditions (evaluation conditions) in which at least one of the illumination conditions (wavelength λ, etc.) of the illumination system 20 and the detection conditions (tilt angle φ2 of the stage 5) of the light receiving system 30 and the imaging unit 35 are different. The calculation result for calculating or estimating the dose amount at the time of exposure of the wafer 10 from the calculation result obtained by performing the calculation for suppressing the change amount with respect to the change of the focus on the detection result obtained by the imaging unit 35 Part 50.

  The evaluation method using the evaluation apparatus 1 includes a step 124 of illuminating the wafer 10 with illumination light, detecting light generated from the surface on which the repeated pattern 12 of the wafer 10 is formed, and the illumination light. Focusing on the detection result obtained by detecting the light generated from the surface under the first and second diffraction conditions in which at least one of the illumination condition and the detection condition of the light generated from the surface of the wafer 10 is different. And steps 128 and 130 for calculating or estimating a dose amount at the time of exposure of the wafer 10 from a calculation result obtained by performing a calculation for suppressing a change amount with respect to a change in position.

  According to this embodiment, using the wafer 10 having the repeated pattern 12 of unevenness provided by exposure under a plurality of exposure conditions as a plurality of processing conditions, the dose amount of the plurality of exposure conditions Can be estimated or evaluated with high accuracy while the influence of the focus position is suppressed. In addition, there is no need to use a separate measurement pattern, and the exposure conditions can be evaluated by detecting light from the wafer on which the actual device pattern is formed. And can be evaluated with high accuracy.

  In addition, the evaluation method exposes the wafer for evaluation while changing at least one of the dose amount and the focus position, and provides a repeated pattern 12 on a plurality of shots on the surface of the wafer to conditionally adjust the wafer 10a (evaluation substrate). , Illuminating the surface of the wafer 10a on which the repeated pattern 12 is provided with illumination light, detecting light generated from the surface by the illumination light, and illumination conditions for the illumination light And a plurality of conditions obtained by detecting light generated from the surface of the conditioned wafer 10a under the first and second diffraction conditions in which at least one of the detection conditions of light generated from the surface of the wafer 10a is different. The first and second diffraction lines that produce a detection result capable of suppressing the amount of change with respect to the change of the focus position using the detection result of Are obtained in advance and stored, and coefficients (gain a and offset b) of the arithmetic expression applied to the two detection results obtained under the first and second diffraction conditions are obtained and stored. Step 114.

Therefore, by obtaining the first and second diffraction conditions in advance, the exposure conditions can be efficiently evaluated with respect to the wafer on which the pattern of the actual device is efficiently formed by performing only two measurements thereafter. it can.
The device manufacturing system DMS (exposure system) of this embodiment includes an exposure apparatus 100 (exposure unit) having a projection optical system that exposes a pattern on the surface of a wafer, and the evaluation apparatus 1 of this embodiment. The exposure condition (processing condition) in the exposure apparatus 100 is corrected according to the first exposure condition (first processing condition) estimated by the calculation unit 50 of the evaluation apparatus 1.

In the exposure method (processing method) of the present embodiment, a pattern is provided by exposure on the surface of the wafer (step 120), and the first exposure condition of the wafer is estimated using the evaluation method of the present embodiment (step 122). To 130), the exposure condition during exposure of the wafer is corrected in accordance with the first exposure condition estimated by the evaluation method (step 134).
As described above, by correcting the exposure condition by the exposure apparatus 100 according to the first exposure condition estimated by the evaluation apparatus 1 or the evaluation method using the same, the wafer actually used for device manufacture is used. Thus, the exposure condition in the exposure apparatus 100 can be set to a target state efficiently and with high accuracy.

In the above embodiment, the dose amount is evaluated while suppressing the influence of the focus position. However, as shown in the flowchart of the main part of the modified example of FIGS. It is also possible to evaluate the focus position while suppressing the influence. This evaluation operation can also be called a focus monitor. In this modified example, in step 112A of FIG. 12A subsequent to step 110 of FIG. 4, the second calculation unit 60b of the inspection unit 60 of FIG. 1A changes the dose from the plurality of diffraction conditions. The first and second diffraction conditions having the same tendency in the curve and the opposite tendency in the focus change curve are selected, and the two selected diffraction conditions are stored in the storage unit 85. As such first and second diffraction conditions, (1-D3) of (n = 1, m = 3) and (1-D4) of (n = 1, m = 4) are selected.
It should be noted that, in step 104 in the condition setting step of FIG. 4 described above, the first diffraction condition (1) among the conditioned wafer images A1 to A13 shown in FIG. 7 obtained under a plurality of diffraction conditions. The image obtained under -D3) is image A3, and the image obtained under the second diffraction condition (1-D4) is image A4. For this reason, the luminance of the image of each part of the wafer 10 imaged under the first and second diffraction conditions is such that the dose amount and the focus value of the part of the wafer 10 are the images A3 and A4, respectively. It becomes almost the same as the brightness of the image of the part which becomes almost the same in the conditionally adjusted wafer.

  FIG. 13A shows two dose change curves C2 and C4 obtained under the diffraction conditions (1-D3) and (1-D4) among the 15 dose change curves shown in FIG. 8B. FIG. 13B shows two focus change curves B3 obtained under the diffraction conditions (1-D3) and (1-D4) among the 15 change curves shown in FIG. 8A. And B4. It can be seen that the dose change curves C2 and C4 change with the same tendency, and the focus change curves B3 and B4 change with the opposite tendency. In the range where the focus value is small, the absolute value of the negative slope of the focus change curve B3 is larger than the absolute value of the negative slope of the focus change curve B4. Therefore, the slope of the curve B3 is within the entire focus value range. It becomes smaller than the slope of the curve B4, and the curves B3 and B4 can be regarded as changing in the opposite tendency.

  The second calculation unit 60b then adjusts the dose change curve C3 obtained under the first diffraction condition (1-D3) with the gain a and the offset b (not shown), and the second diffraction condition (1 The gain a and the offset b are determined so that the dose change curve C4 obtained in -D4) matches, that is, the square sum of the residual ΔC between the corrected curve and the dose change curve C4 is minimized. The gain a and offset b are stored in the storage unit 85 (step 114A). In addition, the vertical axis | shaft of the right side of Fig.13 (a) is the value of residual (DELTA) C.

  Next, the second calculation unit 60b corrects the focus change curve B3 obtained under the first diffraction condition (1-D3) in FIG. 13B with the gain a and the offset b calculated in step 114A. (Not shown) and a curve representing the difference (focus difference) between the focus change curve B4 obtained under the second diffraction condition (1-D4) (hereinafter referred to as a reference focus curve) SF1. And the calculated reference focus curve SF1 is stored in the storage unit 85 (step 116A). The vertical axis on the right side of FIG. 10B is the focus difference value. Further, the reference focus curve SF1 may be approximated by a linear expression or a high-order polynomial regarding the focus value.

  When the focus position, which is the exposure condition of the wafer, is evaluated by the wafer inspection after exposure and development by the exposure apparatus 100, in step 124 of FIG. 5, the first and second selected in step 112A are used. The image of the wafer 10 is taken under the diffraction conditions (1-D3) and (1-D4) of Step 1. In Step 128 of FIG. 5, the gain 10 and offset b stored in Step 114A are used. For each set region, a difference Δni between two average luminances obtained under the first and second diffraction conditions is calculated. Then, following step 128, in step 130 </ b> A of FIG. 12B, the third calculation unit 60 c of the inspection unit 60 stores the entire setting area 16 of the wafer 10 in FIG. By applying the above average luminance difference Δni to the reference focus curve SF1 of b), the corresponding focus value Fni is calculated or estimated. The calculation result or the estimation result is stored in the storage unit 85. From the focus value Fni calculated or estimated in this way, a component due to the dose is removed.

  Thereafter, the control unit 80 converts the focus value Fni into, for example, brightness (or the color may be changed), and calculates the focus distribution (for example, the distribution represented by the image in FIG. 11B) of the entire surface of the wafer 10. The information is displayed on a display device (not shown) (step 136). Further, information on the focus distribution of the entire surface of the wafer 10 is provided from the signal output unit 90 to the exposure apparatus 100 under the control of the control unit 80 (step 134A). In response to this, a control unit (not shown) of the exposure apparatus 100 obtains, for example, a difference distribution between the focus distribution and the best focus position, and if the difference distribution exceeds a predetermined allowable range, for example, auto Adjustment (correction) of a focus mechanism (not shown) is performed. This reduces focus distribution errors during subsequent exposure.

  In the above-described embodiment, a calculation is performed to suppress the influence of one exposure condition on the average luminance obtained from the wafer image obtained under two diffraction conditions. In addition to this, for example, a calculation for suppressing the influence of one exposure condition is performed on three or more brightnesses obtained from an image of a wafer obtained under three or more diffraction conditions. The other exposure condition may be obtained.

Further, in the above-described embodiment, the exposure condition is inspected using the diffraction inspection of the wafer surface by the evaluation apparatus 1, but the PER inspection of the wafer surface by the evaluation apparatus 1 (inspection based on the change in the polarization state of the reflected light). May be used to inspect the exposure conditions.
In the above embodiment, the first and second diffraction conditions (or polarization conditions) in which, for example, the focus change curve has the same tendency and the dose change curve has the opposite tendency from a plurality of diffraction conditions (or polarization conditions). ) Is selected, it is easy to select the first and second diffraction conditions (or polarization conditions). In addition to this, from a plurality of diffraction conditions (or polarization conditions), the difference (or the sum of squares of differences) of the detection result under these conditions, for example, the difference (or the sum of squares of the differences) of the difference in the dose amount (or The first and second diffraction conditions (or polarization conditions) may be selected so that the sum of squares of the differences becomes large.
Furthermore, in the above embodiment, the dose amount and the focus position are evaluated as the exposure conditions. As the exposure conditions, the exposure light wavelength, the illumination conditions (for example, the coherence factor (σ value), and the projection optical system in the exposure apparatus 100 are evaluated. In order to evaluate the numerical aperture of PL or the temperature of the liquid during immersion exposure, the diffraction inspection or PER inspection of the above embodiment may be used.

[Second Embodiment]
A second embodiment will be described with reference to FIGS. 14 (a) to 15 (b). Also in this embodiment, the device manufacturing system DMS in FIG. 1B is used, and the evaluation apparatus 1 in FIG. 1A is used to evaluate the processing conditions. In the present embodiment, the processing conditions of a wafer on which a repetitive pattern with a fine pitch is formed by a so-called spacer double patterning method (or sidewall double patterning method) are evaluated.

  In the spacer double patterning method, first, as shown in FIG. 14A, a plurality of resists are applied to the surface of, for example, the hard mask layer 17 of the wafer 10d by applying resist, exposing the pattern by the exposure apparatus 100, and developing. A repetitive pattern 12 in which the line portions 2A of the pattern are arranged at a pitch P is formed. In the present embodiment, it is assumed that the pitch P is close to the resolution limit of the exposure apparatus 100. Thereafter, as shown in FIG. 14B, the line portion 2A is reduced to a line portion 12A having a line width of 1/2 by slimming, and a spacer layer 18 is deposited so as to cover the line portion 12A with a thin film forming apparatus (not shown). To do. Thereafter, only the spacer layer 18 of the wafer 10d is etched by the etching apparatus 300, and then only the line portion 12A is removed by the etching apparatus 300, whereby the line width is formed on the hard mask layer 17 as shown in FIG. A repetitive pattern is formed in which a plurality of spacer portions 18A of approximately P / 4 are arranged at a pitch P / 2. Thereafter, by etching the hard mask layer 17 using the plurality of spacer portions 18A as a mask, as shown in FIG. 14D, the hard mask portions 17A having a line width of approximately P / 4 are arranged at a pitch P / 2. A repeated pattern 17B is formed. Thereafter, as an example, the repetitive pattern 17B is used as a mask to etch the device layer 10da of the wafer 10d, thereby forming a repetitive pattern having a pitch that is approximately ½ of the resolution limit of the exposure apparatus 100. Furthermore, it is also possible to form a repeated pattern with a pitch of P / 4 by repeating the above steps.

  Further, when performing a diffraction inspection using the evaluation apparatus 1, the pitch of the repetitive pattern must be equal to or greater than ½ of the wavelength λ of the illumination light ILI of the evaluation apparatus 1 in order for diffraction to occur. Therefore, when light having a wavelength of 248 nm is used as illumination light, the diffracted light ILD is not generated in the repetitive pattern 12 having a pitch P of 124 nm or less. Therefore, when the pitch P is close to the resolution limit of the exposure apparatus 100 as in the case of FIG. 14A, the diffraction inspection becomes increasingly difficult. Further, as in the case of FIG. 14D, with respect to the repetitive pattern 17B having a pitch of P / 2 (and further P / 4), only the regular reflection light ILR is generated, so that the diffraction inspection is difficult. However, when there is a pattern block in which the repeated patterns 17B are arranged at a larger pitch, diffraction inspection can be performed by detecting diffracted light from the pattern block.

  In the present embodiment, as shown in FIG. 14D, in order to evaluate the processing conditions of the repetitive pattern 17B by detecting light from the wafer 10d in which the repetitive pattern 17B that does not generate diffracted light is formed in each shot. Then, the PER inspection (inspection based on the change in the polarization state of the reflected light) of the wafer surface by the evaluation apparatus 1 is performed. In the following, referring to the flowchart of FIG. 15 (a), description will be given of setting conditions for selecting a plurality of polarization conditions used when performing the PER inspection, and the selection is made with reference to the flowchart of FIG. 15 (b). A method for evaluating the processing conditions of the device manufacturing system DMS by performing PER inspection using the polarization conditions described above will be described. In FIGS. 15A and 15B, steps corresponding to FIGS. 4 and 5 are denoted by the same or similar reference numerals, and description thereof is omitted or simplified.

  Here, since the PER inspection of the surface on which the repetitive pattern 17B having the pitch P / 2 of the wafer 10d is formed by using the evaluation apparatus 1, as shown in FIG. The tilt angle of the stage 5 on which the polarizing filter 26 and the light receiving side polarizing filter 32 are inserted and on which the wafer 10d is mounted has a light receiving system for the regular reflection light ILR from the wafer 10d irradiated with the illumination light ILI from the illumination system 20. 30 so that light can be received. Further, the rotation angle of the stage 5 is set so that the periodic direction of the repetitive pattern 17B and the incident direction of the illumination light ILI intersect at 45 degrees, for example. As an example of the plurality of polarization conditions, the wavelength λa of the illumination light ILI (any one of the above λ1 to λ3) and the angle θb of the illumination side polarization filter 26 (for example, rotation of the polarization axis with respect to the periodic direction of the repetitive pattern) Assume 15 conditions (λa, θb) (a = 1 to 3, b = 0 to 4) that are combinations of angle and rotation angle 35 degrees + 5 degrees × b (b = 0 to 4). However, when the angle of the illumination side polarizing filter 26 is switched, the angle of the light receiving side polarizing filter 32 is also switched so as to maintain a crossed Nicols state with respect to the illumination side polarizing filter 26. Furthermore, in the present embodiment, as processing conditions of the repeated pattern 17B by the device manufacturing system DMS, the deposition time ts (thin film deposition amount) of the spacer layer 18 and the etching time te (etching amount) of the spacer layer 18 in FIG. And the etching time te is evaluated while suppressing the influence of the deposition time ts.

  First, in order to determine the conditions, in step 102A of FIG. 15, the spacer double patterning process of FIGS. 14A to 14D is performed with five kinds of deposition times ts (ts3 to ts7) and five kinds of etching times. The process is executed by 25 (= 5 × 5) processes in which te (te3 to te7) are combined, and a repeated pattern 17B is formed on each shot of 25 conditionally adjusted wafers (not shown). It is assumed that the deposition time ts5 is the best deposition time (appropriate amount) and the etching time te5 is the best etching time (appropriate etching amount). In this case, the etching times te3 and te4 are insufficiently etched, and the etching times te6 and te7 are excessively etched.

  A plurality of (25 in this case) created conditionally adjusted wafers are sequentially transferred onto the stage 5 of the evaluation apparatus 1 in FIG. Then, in each of the plurality of conditionally adjusted wafers, the surface of the conditionally adjusted wafer is irradiated with the illumination light ILI under the plurality of (here, 15) polarization conditions (λa, θb). An image of the specularly reflected light ILR from the swing wafer is captured and an image signal is output to the image processing unit 40 (step 104A). Here, since 15 images are captured for each of the 25 conditionally adjusted wafers, a total of 375 (= 25 × 15) digital images are obtained in the image processing unit 40.

Further, the image processing unit 40 averages the signal intensities of all the pixels in all shots (or the central region of the shots) of the conditioned wafer using the corresponding digital images for the plurality of polarization conditions. The averaged signal strength (average luminance) is calculated, and the calculation result is output to the inspection unit 60 (step 106A).
Then, the first calculation unit 60a in the inspection unit 60 determines the etching amount (etching time te) in the processing conditions from the average luminance of all the conditionally adjusted wafers obtained for each of the plurality of polarization conditions (λa, θb). And the change characteristic of the average luminance when the deposition amount (deposition time ts) changes in five stages is extracted as a spacer change curve (not shown) and stored in the storage unit 85 (step 108A). In addition, the first calculation unit 60a uses the same average amount of brightness obtained for each of the plurality of polarization conditions (λa, θb) when the deposition amount in the processing conditions is the same and the etching amount changes in five stages. The change characteristic of average luminance is extracted as an etching change curve (not shown) and stored in the storage unit 85 (step 110A).

  After that, the first calculation unit 60a has a tendency that the spacer change curve has the same tendency (for example, when the deposition time ts increases, both average luminances increase / decrease in substantially the same manner from the plurality of polarization conditions (λa, θb). First and second polarizations having a tendency to have opposite characteristics of the etching change curve (for example, a characteristic in which one average luminance is substantially increased and the other average luminance is substantially decreased when the etching time te is increased). The condition is selected, and the two selected polarization conditions are stored in the storage unit 85 (step 112B). FIG. 14 (e) shows two change curves Bk1 and Bk2 obtained under the first and second polarization conditions among the 15 spacer change curves. FIG. 14 (f) shows 15 change curves. Among the etching change curves, two change curves Ck1 and Ck2 obtained under the first and second polarization conditions are shown. The change curves Bk1 and Bk2 change with the same tendency, and the change curves Ck1 and Ck2 change with the opposite tendency.

  Then, the first calculation unit 60a includes a change curve (not shown) obtained by correcting the spacer change curve Bk1 obtained under the first polarization condition with the gain a and the offset b, and the spacer change obtained under the second polarization condition. The gain a and the offset b are determined so that the curve Bk2 coincides, that is, the difference ΔBk between the corrected curve and the curve Bk2 is minimized by the least square method, and the gain a and the offset b are stored in the storage unit. 85 (step 114B). In addition, the vertical axis | shaft of the right side of FIG.14 (e) is the value of difference (DELTA) Bk. If the value of the difference ΔBk becomes relatively large in part, the gain a ′ and the offset b ′ that are different from each other can be set.

  Next, the first calculation unit 60a includes a curve (not shown) obtained by correcting the etching change curve Ck1 obtained under the first polarization condition of FIG. 14F with the gain a and the offset b calculated in step 114B. Then, a curve (hereinafter referred to as a reference etching curve) SE1 in which the difference from the etching change curve Ck2 obtained under the second polarization condition is expressed as a function of the etching time te (etching amount) is calculated, and the calculated reference etching is performed. The curve SE1 is stored in the storage unit 85 (step 116B). Note that the vertical axis on the right side of FIG. 14F is the value of the reference etching curve SE1. Further, the reference etching curve SE1 may be approximated by a linear expression or a high-order polynomial regarding the etching time te. With the above operation, the determination of conditions for obtaining the first and second polarization conditions, which are evaluation conditions used when evaluating the processing conditions, is completed.

  Next, the wafer 10d on which the repeated pattern 17B is formed by the device manufacturing system DMS in the actual device manufacturing process is subjected to polarization inspection by the evaluation apparatus 1, thereby evaluating the etching amount in the processing conditions as follows. To do. This evaluation operation can also be called an etching monitor. First, in step 138 of FIG. 15B, the device manufacturing system DMS executes the spacer double patterning process described with reference to FIGS. A wafer 10d on which 17B is formed is manufactured. The processing conditions at this time are the best deposition time (appropriate amount) for the spacer deposition amount (deposition time ts) and the best etching amount (appropriate amount) for the etching amount (etching time te) in all shots. is there. However, in actuality, there is a possibility that the amount of spacer deposition varies due to uneven film thickness in a thin film forming apparatus (not shown), and there is a possibility that variation in etching amount may occur due to uneven etching in the etching apparatus 300. In this case, if the polarization inspection is simply performed, since the inspection result includes a portion due to the amount of spacer deposition in addition to the etching amount, the influence of the amount of spacer deposition is eliminated as follows. .

The manufactured wafer 10d is loaded onto the stage 5 of the evaluation apparatus 1 shown in FIG. 2A via an alignment mechanism (not shown) (step 122A). Then, the evaluation apparatus 1 captures an image of the wafer 10d under the first and second polarization conditions determined by the above conditions and outputs an image signal to the image processing unit 40 (step 124A). .
Next, the image processing unit 40 generates a digital image of the entire surface of the wafer 10d with respect to each of the first and second polarization conditions. Then, with respect to the first and second polarization conditions, the average signal intensity (average) for each of a plurality of setting regions 16 (see FIG. 6C) in all shots of the wafer 10d using the corresponding digital images. (Luminance) is calculated, and the calculation result is output to the inspection unit 60 (step 126). Then, the third calculation unit 60c in the inspection unit 60 calculates the average brightness obtained under the first polarization condition for each of all the setting regions 16 of the wafer 10d by the gain a and the offset b calculated in the above step 114B. The average luminance obtained under the second polarization condition is subtracted from the luminance corrected in step (b) to calculate the average luminance difference Δni, and the calculation result is stored in the storage unit 85 (step 128). From this difference Δni, components corresponding to the spacer change curves Bk1 and Bk2 in FIG. 14E are substantially removed, and components corresponding to the corrected difference in the etching change curves Ck1 and Ck2 in FIG. Only almost remains.

  Therefore, the third calculation unit 60c applies the difference Δni in the average brightness to the reference etching curve SE1 in FIG. 14F stored in the step 116B for every setting region 16 of the wafer 10d. The etching amount (etching time) teni is calculated or estimated, and the calculation result or the estimation result is stored in the storage unit 85 (step 140). From the etching amount teni calculated or estimated in this way, components due to the spacer deposition time are removed. Thereafter, the control unit 80 converts the etching amount teni into, for example, brightness (or the color may be changed) and displays etching unevenness on the entire surface of the wafer 10d on a display device (not shown) (step 142). Further, under the control of the control unit 80, information on the etching unevenness of the entire surface of the wafer 10 is provided from the signal output unit 90 to the etching apparatus 300 via the host computer 600 (step 144). In response to this, a control unit (not shown) of the etching apparatus 300 obtains, for example, a difference distribution between the etching unevenness and the appropriate etching amount, and if the difference distribution exceeds a predetermined allowable range, for example, etching is performed. Corrections such as part adjustments are performed. As a result, the etching unevenness is reduced during the subsequent execution of step 138 (spacer double patterning process), and the repeated pattern 17B having the pitch P / 2 can be manufactured with high accuracy.

According to this embodiment, by performing PER inspection under two polarization conditions using the wafer 10d on which the repetitive pattern 17B for an actual device is formed, in the etching apparatus 300 used at the time of forming the pattern It is possible to estimate or evaluate the etching amount with high accuracy by removing the influence of the deposition amount of the spacer.
Similarly, by performing a PER inspection under two polarization conditions, it is possible to estimate or evaluate the amount of spacer deposition with high accuracy by removing the influence of the etching amount.

Further, as processing conditions in the double patterning process, in addition to the etching amount and the spacer deposition amount, for example, a dose amount and a focus position at the time of exposure in the exposure apparatus 100 can be considered.
Further, in the above-described embodiment, the exposure apparatus 100 is a scanning stepper that uses an immersion exposure method, but the above-described embodiment is also used when an exposure apparatus such as a dry scanning stepper or a stepper is used as the exposure apparatus 100. The same effect can be obtained by applying. Further, when the exposure apparatus 100 uses an EUV exposure apparatus that uses EUV light (Extreme Ultraviolet Light) having a wavelength of 100 nm or less as exposure light, or an electron beam exposure apparatus that uses an electron beam as an exposure beam, the above-described implementation is performed. Form can be applied.

  Further, as shown in FIG. 16, a semiconductor device (not shown) includes a design process (step 221) for designing the function and performance of the device, and a mask manufacturing process (mask) for manufacturing a mask (reticle) based on the design process (step 221). Step 222), a substrate manufacturing process (Step 223) for manufacturing a wafer substrate from a silicon material or the like, a substrate processing process (Step 224) for forming a pattern on the wafer by the device manufacturing system DMS or a pattern forming method using the same. It is manufactured through an assembly process (step 225) including a dicing process for assembling a device, a bonding process, a packaging process, and the like, and an inspection process (step 226) for inspecting the device. In the substrate processing step (step 224), a resist is applied to the wafer by the device manufacturing system DMS, an exposure step of exposing the reticle pattern to the wafer by the exposure apparatus 100 in the device manufacturing system DMS, and development for developing the wafer. A lithography process including processes and an evaluation process for evaluating exposure conditions and the like using light from the wafer are executed by the evaluation apparatus 1.

In such a semiconductor device manufacturing method, the exposure conditions and the like are evaluated using the evaluation apparatus 1 described above. For example, by correcting the exposure conditions and the like based on the evaluation result, the manufacturing process becomes a good state, and the final The yield of the semiconductor manufactured can be improved.
In the device manufacturing method of the present embodiment, the method of manufacturing a semiconductor device has been particularly described. However, the device manufacturing method of the present embodiment can be applied to a semiconductor material such as a liquid crystal panel or a magnetic disk in addition to a device using a semiconductor material. The present invention can also be applied to the manufacture of devices using other materials.

  In addition, this invention is not limited to the above-mentioned embodiment, A various structure can be taken in the range which does not deviate from the summary of this invention.

  DESCRIPTION OF SYMBOLS 1 ... Evaluation apparatus, 5 ... Stage, 10 ... Wafer, 10a ... Conditional wafer, 20 ... Illumination system, 30 ... Light receiving system, 35 ... Imaging part, 40 ... Image processing part, 50 ... Calculation part, 60 ... Inspection part, 85 ... Storage unit, 100 ... Exposure apparatus, DMS ... Device manufacturing system

Claims (14)

An illumination unit that illuminates a substrate having a structure provided by processing under a plurality of processing conditions including first and second processing conditions with illumination light;
A detection unit for detecting light generated from the processing surface of the substrate by the illumination light;
An operation for calculating a detection result obtained by the detection unit under a plurality of diffraction conditions and outputting a calculation result for estimating the first processing condition or the second processing condition at the time of processing the substrate. And
The first processing condition when processing the substrate based on detection results obtained by the detection unit under a plurality of evaluation conditions in which at least one of the illumination condition of the illumination unit and the detection condition of the detection unit is different And an estimation unit for estimating at least one of the second machining conditions;
Equipped with a,
The detection unit detects reflected or diffracted light from the processing surface of the substrate,
The plurality of evaluation conditions are evaluation devices having different diffraction conditions . The plurality of evaluation conditions include first and second evaluation conditions,
The estimation unit estimates at least one of the first machining condition and the second machining condition from a difference between the detection result obtained under the first evaluation condition and the detection result obtained under the second evaluation condition. The evaluation apparatus according to claim 1.   At least one of a process of adding an offset and a process of giving an arbitrary magnification to at least one detection value of the detection result obtained under the first evaluation condition and the detection result obtained under the second evaluation condition The evaluation apparatus according to claim 2, which is a difference after performing. Processing the substrate includes exposing the substrate through a projection optical system;
One of the first and second processing conditions is an exposure amount at the time of exposure of the substrate,
4. The evaluation apparatus according to claim 1, wherein the other of the first and second processing conditions is an in-focus state with respect to the projection optical system during exposure of the substrate.   An exposure unit having a projection optical system that exposes a pattern on the surface of the substrate;
  An evaluation device according to any one of claims 1 to 4,
  An exposure system that corrects a processing condition in the exposure unit according to the first processing condition estimated by the estimation unit of the evaluation apparatus.   Illuminating a substrate having a structure provided by processing under a plurality of processing conditions including first and second processing conditions with illumination light;
  Detecting light generated from the processing surface of the substrate by the illumination light;
  A detection result obtained by the detection unit under a plurality of diffraction conditions is calculated, and a calculation result for estimating the first processing condition or the second processing condition at the time of processing the substrate is calculated. ,
  A detection result obtained by detecting light generated from the processing surface under a plurality of evaluation conditions in which at least one of the illumination conditions of the illumination light and the detection conditions of light generated from the processing surface is different Based on estimating at least one of the first processing condition and the second processing condition when processing the substrate,
  When detecting light generated from the processing surface of the substrate, the reflected or diffracted light from the processing surface is detected,
  The plurality of evaluation conditions are evaluation methods having different diffraction conditions.   The plurality of evaluation conditions include first and second evaluation conditions,
  At the time of the estimation, at least one of the first machining condition and the second machining condition from the difference between the detection result obtained under the first evaluation condition and the detection result obtained under the second evaluation condition. The evaluation method according to claim 6, wherein   At least one of a process of adding an offset and a process of giving an arbitrary magnification to at least one detection value of the detection result obtained under the first evaluation condition and the detection result obtained under the second evaluation condition The evaluation method according to claim 7, which is a difference after being performed.   Processing the substrate includes exposing the substrate through a projection optical system;
  One of the first and second processing conditions is an exposure amount at the time of exposure of the substrate,
  The evaluation method according to any one of claims 6 to 8, wherein the other of the first and second processing conditions is a focused state with respect to the projection optical system at the time of exposure of the substrate.   Processing the evaluation substrate while changing at least one of the first and second processing conditions, and providing the structure in a plurality of regions of the processing surface of the evaluation substrate,
  Illuminating the processing surface of the evaluation substrate with the illumination light,
  Detecting light generated from the processing surface of the evaluation substrate by the illumination light;
  Light generated from the processing surface with respect to the evaluation substrate under a plurality of conditions in which at least one of the illumination condition of the illumination light and the detection condition of light generated from the processing surface of the evaluation substrate are different 10. The plurality of evaluation conditions that produce a detection result that can suppress a change amount with respect to a change in the second machining condition using a plurality of detection results obtained by detecting the above-mentioned are obtained and stored in advance. The evaluation method according to any one of the above.   When the plurality of evaluation conditions are obtained and stored in advance, the detection result obtained by detecting light generated from the processing surface of the substrate under the plurality of evaluation conditions is included in the detection result of the second processing condition. The evaluation method according to claim 10, wherein an arithmetic expression applied to suppress a change amount with respect to a change is obtained and stored.   A pattern is formed on the surface of the substrate by processing,
  The first processing condition of the substrate is estimated using the evaluation method according to any one of claims 6 to 11.
  A processing method for correcting processing conditions at the time of exposure of the substrate in accordance with the first processing conditions estimated by the evaluation method.   A device manufacturing method having a processing step of providing a pattern on a surface of a substrate,
  A device manufacturing method using the processing method according to claim 12 in the processing step.   A device manufacturing method having a processing step of providing a pattern on a surface of a substrate,
  Using the processing method according to claim 12 in the processing step,
  A device manufacturing method for storing an arithmetic expression applied to suppress a change amount with respect to a change in the second processing condition in accordance with a device to be manufactured.

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